BOWL drying kiln from an old freezer

[allen thunem]

Have seen and heard of UPRIGHT freezers being converted to bowl drying kilns using simple techniques and parts.
Would love to hear others experiences and thoughts on how to build one using lightbulbs and computer fans etc etc.
I am a big advocate of the K.I.S.S. PRINCIPLE
looking forward to hearing your thoughts

[philip labre]

I built one but didn't put a fan in it and the bowls closest to the bulb tended to dry a bit too quick. Otherwise worked well.

[Randy Red Bemont]

I saw something on this very subject on another forum. I'll have to look around and find it. They talk about what watt bulb for what temp and so on. It was interesting.

Red

[Doug Herzberg]

Allen, I made mine from an old fridge. The heat is from a light bulb connected to a thermostat and it is plenty, even on the coldest days. Sometimes I don't notice when the light bulb burns out, though, and everything freezes in my unheated shop. That isn't good. With incandescent light bulbs going off the shelves, I'm thinking about replacing the light bulb with a small baseboard heater or some other safe heat source.

I bought a humidistat I intend to pair with a fan, but haven't gotten around to it yet. I've had a few instances of mold growing on my blanks, so I think it will be a good addition.

[Dale Bonertz]

Instead of using light bulbs, which add up in cost and as Doug mentioned they burn out, use a oven heating element or a dishwasher heating element. They both can be purchased cheap and hooked up to a thermostat and purchased for 120volt. My 230volt heating element for my larger kiln was $15. A fan/air movement really is a must for any kiln and should blow over the heating element ideally to disperse the heat quicker and not cause problems for the lower bowls. Also cover the element and fan some safe way so water and anchor seal are not dripping on them all the time. The kiln will accumulate water in the lower pan so best to keep any heating source a little elevated. You also, sometimes of the year, may have trouble keeping the temperature down so install an air vent on the top to release some heat if needed. OK so maybe I just complicated it for you.

[Doug Herzberg]

Instead of using light bulbs, which add up in cost and as Doug mentioned they burn out, use a oven heating element or a dishwasher heating element. They both can be purchased cheap and hooked up to a thermostat and purchased for 120volt. My 230volt heating element for my larger kiln was $15. A fan/air movement really is a must for any kiln and should blow over the heating element ideally to disperse the heat quicker and not cause problems for the lower bowls. Also cover the element and fan some safe way so water and anchor seal are not dripping on them all the time. The kiln will accumulate water in the lower pan so best to keep any heating source a little elevated. You also, sometimes of the year, may have trouble keeping the temperature down so install an air vent on the top to release some heat if needed. OK so maybe I just complicated it for you.

I've been thinking about this for a few months now. As a landlord, I often have old appliances, but I haven't replaced a dishwasher in awhile and the oven elements I have, I'm keeping for future repairs.

I did just take in a big old frost-free fridge. This has a (defrost) heating element and I was thinking about pulling it to use to heat my kiln. It occurred to me that the fridge it currently occupies has the element located in a safe place and also has a circulating fan in close proximity. It seems like a new 110v thermostat with the proper temperature range and a little rewiring might be the most elegant solution. The element and circulating fan could come on when the T-stat calls for heat. One could add a vent and small computer fan, perhaps wired to a dehumidistat to eliminate excess moisture.

Has anyone tried this? See any problems?

[robert baccus]

Most of the very active turners on here produce many pieces and have never seen a drying cabinet. Is it really necessary? Endseal is the best device ever for controlled drying.

[Doug Herzberg]

Most of the very active turners on here produce many pieces and have never seen a drying cabinet. Is it really necessary? Endseal is the best device ever for controlled drying.

Robert, my experience is very limited, but a roughed out bowl in a heated, controlled cabinet seems to dry a lot faster (weeks instead of months) than one left on my basement floor in a paper bag or with end grain sealed. I often seal the endgrain of species prone to checking before before they go into the kiln. Also, I can keep the kiln in my unheated shop where wild temperature swings would otherwise wreak all sorts of havoc. SWMBO will only allow me so much space in the house, even in the basement.

[Reed Gray]

As near as I can tell, the kilns do make a difference with twice turned bowls. Not worth the effort with once turned bowls. If you do enough quantity, it may not be necessary as they will dry fine in a separate room. Maybe add a dehumidifier. Much depends on the wood and your local climate.

robo hippy

[robert baccus]

The climate does make a difference, no question. Colorado springs has a very low average RH--I would think that slowing the drying would be more important there. Real kiln drying is very complicated --humidity as well as temperature is controlled. This varies with species which is why tropical hardwoods are so difficult to harvest and market.

[Paul Gilbert]

When converting an upright frost free refrigerator or freezer for use as a kiln, you can certainly use the circulating fan and associated duct work. The defrost heater can be used, but a resistor will be necessary to regulate its' heat output. Unregulated it will get way too hot to maintain a constant temp. in the kiln. I would use a lamp dimmer switch in the circuit to regulate this.

[Reed Gray]

I have wondered in the past how come no one just makes an upright box with a door, shelves, and a small watt light bulb in the bottom. Hole size in the top would determine how much of a convection current is allowed because hot air rises.

robo hippy

[Doug Herzberg]

I have wondered in the past how come no one just makes an upright box with a door, shelves, and a small watt light bulb in the bottom. Hole size in the top would determine how much of a convection current is allowed because hot air rises.

robo hippy

Reed, around here we need the insulation and door seal that come with an icebox or freezer to keep the heat in. I think convection would work to some extent. So far, I haven't done anything to vent or circulate air, other than place the bulb at the bottom, but I have had some mold issues.